Hot-air heating apparatus



.111; POWERS HOT AIR HEATING APPARATUS Filed Nov. s, 1922 2 Sheets-Sheet 1 IN.'ENTOR :WITNESSE ATTORNEY mm mw J. IF. POWERS HOT AIR HEATING APPARATUS 2 Sheets-Sheet 2 Filed Nov 5 INVENTOR W 2 ff'w A TORNEY WITNESSES in a di lhllllfi rewrite, or mirwoon, rnnnsrtvaina.

application filed November il'o all (whom may concern: 1

Be it known that l, ilari'nsl Powers, a citizenv of the UIH'lJQCl States, reslding at .liinwood in the county of Delaware and Estate of. Pennsylvania, have invented new and? useful ltmprovements in idiot-air l'leat- 111g. Apparatus, of which the following is a specification. p

Uneobject of my said in vention the p rovision of a highly eflicient air heating unit designed for interposition between the usual combustion chamber and smoke drum of a hotair furnace.

Anotheuobject of the invention the provision of a hot air heating furnace embodying the said unit which is characterized by the capacity OillxCOlltlliCtlDg the products of, combustion through a long tortuous course en route between the combustion chamber and, the smoke drum and is also characterized by an extremely large radiatingsurface in proportion to its size. TO the attainment of the foregoing, the invention consists in the improvement as hereinafter described and definitely claimed. In the accompanying drawings, forming part of this specification Figure 1 is a view partly in vertlcal sec tion and partly in side elevation of a furnace embodying my improvement.

Figure 2 is a detaildiametrica-l section through my novel interposed unit and also through the smoke drum and the upper portion of the combustion chamber.

Figure 3 is a full horizontal section taken through the furnacein the plane indicated by the line 33 of Figure 1..

Similar numerals of reference designate corresponding parts in all of the views of the drawings.

Generally speaking the furnace is of the ordinary well known construction including inner and outer casing walls 1 and 2, the space 3 between which is in communication with the floor register a andwith the lower portion of the chamber formed by the inner wall 1, Figure 1.

l vithin the inner casing wall is arranged a combustion chamber 7 of the ordinary construction or any other construction compatible with the purpose of my invention. Also withinthe inner casing wall 1 and at a point adjacent to the crown 5 is arranged the smoke drum 8 which is in communica tion with an uptake 9.

The illustrated appurtenances of the a, Serial no. teases.

combustion chamber 7 and the casing formed by the walls 1 and 2 may be and preferably are of the ordinary well known construction and need not therefore be described in detail.

In accordance with my invention l. in terpose. between and. appropriately join to the combustion chamber 7 and the smoke drum 8 aunit 10 which is best shown in lfi igures 1 and 2; The said unit 10 is formed of castiron and includes a hollow body or core 11, a central depending conduit 12, a central upwardly extending conduit 13, and iaSPlIELl conduit 14!: which surrounds the body or core 11 and has its convolutions separated by an intervening spiral space 15. Thelower end of the said spiral conduit 14: is in lateral communication at 16 with the lower central conduit 12, and the upper end of the said spiral conduit 14: is in lateral communication at 17 with the upper central conduit 13. In virtue of this it will be manifest that en route between the combustion chamber 7 and the smoke drum 8 the flames and other products of combustion will traverse a long tortuous course, and throughout the length of the said tortuous course the flames and other products of combustion will highly heat the walls of the spiral conduit 14-, and the said walls will give off heat by radiation with the result that the air within the inner casing wall 1 and the air within the spiral space 11 will be highly heated, so that bthe time the products of combustion reac the drum 8 practically all of the heat value of the products of combustion will be given off to the air within the casing wall 1. In this connection it will be understood that fresh air is supplied from the space 3 to the lower portion of the chamber within the wall 1. This air will pass upwardly in the furnace casing and will be discharged through the floor register 5 into an apartment. its before indicated the unit 10 is formed of cast metal with a hollow body or core 11, the said hollow body or core 11 being shown as provided with plugged apertures 19 for the removal of the sand or other material used in the molding operation.

At 20 the unit 10 is preferably though not necessarily, provided with clean out doors. lit will also be noted by reference to Figure 2 that the joints between the unit 10 on the one hand and the combustion chamber 7 and smoke drum 8, on the other, are rabbet joints, this provision being highly desirable inasill) much as it renders it feasible to int-erpose my novel unit 10 between an ordinary combustion chamber 7 and an ordinary smoke drum 8 such as are to be found in furnaces at present in use. From this it follows that when deemed expedient my novel unit 10 may be substituted for the usual connection employed between the combustion chamber and the smoke drum of a hot air furnace, my said unit being highly desirable because of the long spiral conduit 14, and the arrangement of the convolutions of the said conduit whereby a radiating surface of great length and area is afforded to utilize practically all of the heat in the escaping products of combustion to raise the temperature ofthe air within the furnace casing.

I have entered into a detailed description of the construction and relative arrangement of the parts embraced in the present and preferred embodiment of my invention in order to impart a full, clear and exact understanding of the said embodiment. I do not desire, however, to be understood as confining myself to the specific construction and relative arrangement of parts inasmuch as in the future practice of the invention various changes and modifications may be made such as fall within the scope of my invention as defined in my appended claims.

Having described my invention, what I claim and desire to secure by Letters- Patent, is

1. As a new article of manufacture, a unit for use in hot air furnaces, comprising a lower central conduit, an upper central conduit, a body or core interposed between the said central conduits, and a spiral conduit surrounding the lower and upper central conduits and the body or core, and having its lower end in lateral communication with the lower conduit and its upper end in lateral communication with the upper conduit and also having its convolutions separated by a spiral space whereby all portions of the wall of the spiral conduit are utilized for heat radiating purpose.

2. As a new article of manufacture, a unit for use in hot air furnaces, comprising a lower central conduit, an upper central conduit, a body or core interposed between the said central conduits, and a spiral conduit surrounding the lower and upper central conduits and the body or core, and having its lower end in lateral communication with the lower conduit and its upper end in lateral communication with the upper conduit and also having its convolutions separated by a spiral space whereby all portions of the wall of the spiral conduit are utilized for heat radiating purposes; the said core or body of the unit being hollow and isolated from the lower and upper central conduits and spiral conduit, and the said spiral conduit being provided at intervals in its length with clean out doors.

3. The combination in a hot air furnace, of a drum spaced above the combustion chainber. and a unit interposed between and joined to the combustion chamber and the smoke drum and having lower and upper central conduits and a body or core intern'iediate of said conduits and also having a spiral conduit surrounding the said central conduits and the body or core; said spiral conduit communicating laterally at its lower end with the lower central conduit and communicating laterally at its upper end with the upper central conduit and being arranged with a spiral space between its convolutions, whereby all of the wall of the spiral conduit is utilized for heat radiating purposes.

In testimony whereof I afiix my signature.

JAMES F. POWERS. 

